Nanoplatelet-strengthened nickel-based multi-principal element alloy and design method and preparation method thereof

Abstract

The application provides a nanosheet layer epsilon phase reinforced nickel-based multi-principal element alloy and a design method and a preparation method. The alloy comprises a base gamma phase and a nanoscale epsilon phase sheet layer. The nanoscale epsilon phase sheet layer is uniformly distributed in the base gamma phase. The composition of the nickel-based multi-principal element alloy comprises 22-25 at.% Co, 22-25 at.% Cr, 1-4 at.% Nb, 0-4 at.% V, 0-1 at.% Ta, and the balance of Ni. The application can significantly improve the high-temperature mechanical properties of the nickel-based alloy and fundamentally solve the problem that the epsilon phase in the nickel-based alloy cannot provide sufficient high-temperature strength.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-temperature alloy design and processing manufacturing technology, in particular to a kind of nanosheet ε phase reinforced nickel-based multi-principal element alloy and design method and preparation method. BACKGROUND

[0002] Nickel-based alloys are widely used in aerospace, power plants, nuclear and petrochemical industries. Precipitation strengthening is the main strengthening way of nickel-based superalloys, and ordered γ'-Ni3Al (L12 structure) and γ"-Ni3Nb phase (D0 22 structure) are one of the most common strengthening phases in nickel-based alloys. Studies have shown that γ" phase can provide better low-temperature strengthening effect than γ', mainly because γ" phase has higher reverse domain boundary energy and higher lattice mismatch (about ~ 2.9%).

[0003] However, γ" phase is a metastable form of Ni3Nb, which is easy to quickly destabilize into δ phase (in nickel-based superalloys)

[16] or D0 a structure of D0 19The ε phase of the structure (in some multi-principal element alloys) [G. H. Xia, Z. L. Ma, Z. Q. Xu, M. Wang, X. W. Cheng, H. N. Cai, Novel high-entropy alloys with high-density ε-D019 and abnormal phase transformation, Scripta Materialia 199 (2021) 113893]. This γ''→δ phase transformation in nickel-based superalloys usually occurs at 650 °C [A. S. M. H. Committee, Properties and Selection: Irons, Steels, and High-Performance Alloys, ASM International, 1990.] during service or thermal stress coupled aging processes, and is accompanied by a sharp decrease in strength. This reduction in strength is due to the fact that the δ phase is always incoherent with the γ matrix [X. Liu, J. Fan, Y. Song, P. Zhang, F. Chen, R. Yuan, J. Wang, B. Tang, H. Kou, J. Li, High-temperature tensile and creep behaviour of Inconel 625 superalloy sheet and its associated deformation-failure micromechanisms, Materials Science and Engineering: A 829 (2022) 142152.] which cannot impart similar high-temperature strength levels. Although the coherent ε phase has been shown to be beneficial for the high-temperature strength of certain high-entropy alloys [G. H. Xia, Z. L. Ma, Z. Q. Xu, M. Wang, X. W. Cheng, H. N. Cai, Novel high-entropy alloys with high-density ε-D019 and abnormal phase transformation, Scripta Materialia 199 (2021) 113893], it still cannot be compared with the γ'' phase. The poor stability of the γ'' phase and the insufficient high-temperature strengthening of the stable phases (δ and ε) severely limit the development of γ''-strengthened alloys and restrict their application at medium temperature conditions.

[0004] Currently, the main solution to the problem of strength reduction of γ" phase strengthened nickel-based superalloys above 650℃ is to improve the stability of γ" phase. However, since the stabilization transformation of γ" phase cannot be avoided during high-temperature service, this method cannot fundamentally solve the problem. Therefore, there is an urgent need for a nickel-based alloy design and preparation method that can improve the high-temperature strength of δ or ε phase.

[0005] After searching, there is no patent disclosure on ε phase strengthened alloy high temperature strength, and only one patent disclosure on δ phase strengthened alloy high temperature strength. A Chinese invention patent with application publication number CN 113249620 A discloses a new ε phase strengthened nickel-based superalloy and a preparation method thereof. The alloy includes 8%-18% Cr, 8%-18% Co, 2.5%-6.5% W, 3%-6% Mo, 30%-45.5% Nb, 3%-10% Al and 30%-45% Ni by mass percentage; wherein the new ε phase strengthened nickel-based superalloy uses intermetallic compound Nb3Al as the strengthening phase, the strengthening phase in the alloy is uniformly distributed in the matrix and forms good metallurgical bonding with the γ-matrix, which can meet higher use temperature. However, this patent mainly relies on the method of powdering-milling-hot isostatic pressing to prepare δ phase strengthened nickel-based superalloy, which has a long process flow and low production efficiency. SUMMARY

[0006] In view of the defects in the prior art, the purpose of the present application is to provide a nanosheet ε phase strengthened nickel-based multi-principal element alloy and a design method and a preparation method.

[0007] According to a first aspect of the present application, a nanosheet ε phase strengthened nickel-based multi-principal element alloy is provided, comprising a matrix γ phase and a nanoscale ε phase sheet layer, the nanoscale ε phase sheet layer is uniformly distributed in the matrix γ phase, the composition of the nickel-based multi-principal element alloy includes 22-25 at.% Co, 22-25 at.% Cr, 1-4 at.% Nb, 0-4 at.% V, 0-1 at.% Ta, and the balance is Ni.

[0008] Optionally, the volume fraction of the nanoscale ε phase sheet layer in the nickel-based multi-principal element alloy is 15%-40%.

[0009] Optionally, the sheet layer spacing of the nanoscale ε phase sheet layer is 120-200 nm, and the sheet layer thickness is 30-50 nm.

[0010] Optionally, the nanoscale ε phase sheet layer and the matrix γ phase are in a semi-coherent state, and the mismatch degree is 1-3%; preferably, the mismatch degree is 1.48%.

[0011] According to a second aspect of the present application, a design method for the above-mentioned nanosheet ε phase strengthened nickel-based multi-principal element alloy is provided, the design method comprises:

[0012] Ni, Co and Cr are selected as the base elements of the nickel-based multi-principal element alloy master alloy, and the contents of the base elements in the master alloy are determined according to the Thermo-Calc thermodynamic calculation results;

[0013] Nb is added to the master alloy as an ε phase forming element, so as to obtain as high ε phase solubility temperature as possible on the premise that no third phase other than γ and ε is precipitated, and the content of Nb is determined according to the principle;

[0014] V is added as an ε phase forming element, so as to obtain as high ε phase solubility temperature as possible on the premise that no third phase other than γ and ε is precipitated, and the content of V is determined according to the principle;

[0015] Ta is added as a strong ε phase forming element, so as to obtain as high ε phase volume fraction as possible on the premise that no third phase other than γ and ε is precipitated, and the content of Ta is determined according to the principle.

[0016] According to a third aspect of the present application, a preparation method of the above-mentioned nanosheet ε phase strengthened nickel-based multi-principal element alloy is provided, and the preparation method comprises:

[0017] First, the component raw materials of the nickel-based multi-principal element alloy are smelted and subjected to high-temperature homogenization treatment;

[0018] Then, the alloy is subjected to cold rolling treatment;

[0019] Then, recrystallization treatment is performed;

[0020] Finally, aging treatment is performed at a temperature at which ε phase discontinuous precipitation occurs, so as to obtain the nanosheet ε phase strengthened nickel-based multi-principal element alloy.

[0021] Optionally, the component raw materials of the nickel-based multi-principal element alloy are smelted and subjected to high-temperature homogenization treatment, and the temperature of the homogenization treatment is 1180-1230℃.

[0022] Optionally, the alloy is subjected to cold rolling treatment, and the deformation amount of the cold rolling treatment is greater than 80%.

[0023] Optionally, the recrystallization treatment comprises: recrystallization treatment at 1130-1200℃ for 5-8 minutes.

[0024] Optionally, the aging treatment is performed at a temperature at which ε phase discontinuous precipitation occurs, and the temperature at which the ε phase discontinuous precipitation occurs is 780-820℃, and the aging treatment is performed for 5-1000 hours.

[0025] Compared with the prior art, the present application has at least one of the following beneficial effects:

[0026] 1. The nickel-based multi-principal element alloy of the present application comprises a matrix gamma phase and nanoscale epsilon phase lamellae, and the nanoscale epsilon lamellae strengthening phase can significantly improve the high-temperature mechanical properties of the nickel-based alloy, and fundamentally solve the problem that the epsilon phase in the nickel-based alloy cannot provide sufficient high-temperature strength.

[0027] 2. The present application utilizes the characteristic that the epsilon phase will undergo discontinuous precipitation at 780-820℃ to prepare a nickel-based alloy strengthened by nanoscale epsilon phase lamellae; the nanoscale epsilon lamellae strengthening phase can significantly improve the mechanical properties at 25℃ to 700℃, increasing the yield strength at 25℃ by 90-120% and at 700℃ by 70-100%; the nanoscale epsilon lamellae strengthened nickel-based alloy still maintains good plasticity (tensile elongation of 17%-25%) at 600℃ to 800℃.

[0028] 3. The present application mainly relies on alloy composition design combined with process and heat treatment process optimization to obtain a nanoscale epsilon lamellae strengthened nickel-based alloy, without adding noble metal elements and without using processes other than casting, cold rolling and heat treatment, thus not increasing additional costs. BRIEF DESCRIPTION OF DRAWINGS

[0029] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the attached drawings:

[0030] Figure 1 Thermo-Calc thermodynamic software calculation results for an embodiment of the present application;

[0031] Figure 2 SEM image of the Ni-Co-Cr-Nb quaternary alloy of Example 1 of the present application aged at 800℃ for 1000 hours;

[0032] Figure 3 SEM image of the Ni-Co-Cr-Nb-V quinary alloy of Example 2 of the present application aged at 800℃ for 700 hours;

[0033] Figure 4 SEM image of the Ni-Co-Cr-Nb-V-Ta quinary alloy of Example 3 of the present application aged at 800℃ for 100 hours;

[0034] Figure 5 Mechanical property comparison curve of the Ni-Co-Cr-Nb-V-Ta quinary alloy of Example 3 of the present application after aging at 800℃ for 100 hours;

[0035] Figure 6 TEM image of the Ni-Co-Cr-Nb-V-Ta quinary alloy of Example 4 of the present application aged at 800℃ for 5 hours. DETAILED DESCRIPTION

[0036] The application will be described in detail below with reference to specific embodiments. The following embodiments will help those skilled in the art to further understand the application, but do not limit the application in any form. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the application. These all belong to the protection scope of the application.

[0037] The design method of the nanosheet ε phase strengthened nickel-based multi-principal element alloy provided by an embodiment of the application comprises the following steps:

[0038] S1, selecting Ni, Co and Cr as the base elements of a nickel-based multi-principal element alloy parent alloy (i.e. a matrix γ phase), and determining the content of the base elements in the parent alloy according to Thermo-Calc thermodynamic calculation results. The Thermo-Calc thermodynamic calculation results are as shown in Figure 1 Figure 1 In the above table, (a) represents an alloy containing no V and containing only Nb, i.e. a Ni-Co-Cr-Nb alloy; (b) represents an alloy containing no Ta, i.e. a Ni-Co-Cr-Nb-V alloy; and (c) represents a Ni-Co-Cr-Nb-V-Ta alloy.

[0039] According to the Thermo-Calc thermodynamic calculation results, the maximum contents of Co and Cr are taken under the premise of ensuring that no laves phase and σ phase are precipitated, i.e. Co: 22-25 at.%, Cr: 22-25 at.%, and Ni: the balance, so as to obtain a better solid solution strengthening effect and oxidation resistance effect.

[0040] S2, adding ε phase (ε-Ni3Nb phase) main forming element Nb to the parent alloy, so as to obtain the highest possible ε phase solubility temperature under the premise that no third phase other than γ and ε is precipitated, determine the content of the Nb element, and form a Ni-Co-Cr-Nb quaternary alloy.

[0041] According to the Thermo-Calc thermodynamic calculation results, when the content of the Nb element exceeds 4 at.%, the σ phase will be precipitated in the alloy. Accordingly, the content range of the Nb element is determined to be 1-4 at.%, so as to avoid the precipitation of the σ phase.

[0042] S3, adding ε phase forming element V to the Ni-Co-Cr-Nb quaternary alloy, the V element is beneficial to promoting the precipitation of the ε phase, and can further improve the volume fraction of the ε phase in the alloy; the content of the V element is determined according to the principle of obtaining the highest possible ε phase solubility temperature under the premise that no third phase other than γ and ε is precipitated, and a Ni-Co-Cr-Nb-V quinary alloy is formed.

[0043] ​According to the Thermo-Calc thermodynamic calculation results, when the content of V element is 0-4 at.%, the dissolution temperature of ε phase in the alloy gradually increases; when the content of V is greater than 4 at.%, the dissolution temperature of ε phase in the alloy gradually decreases. Therefore, the content range of V element is determined to be 0-4 at.%.

[0044] S4, further adding strong ε phase forming element Ta to the Ni-Co-Cr-Nb-V five-element alloy, aiming to further increase the solid solution temperature and volume fraction of ε phase in the alloy. According to the principle of obtaining the highest possible ε phase volume fraction without precipitating a third phase other than γ and ε, the content of Ta element is determined;

[0045] According to the Thermo-Calc thermodynamic calculation results, when the content of Ta element is 0-1 at.%, the dissolution temperature of ε phase in the alloy gradually increases, and the volume fraction of ε phase in the alloy is significantly increased, but when the content of V is greater than 1 at.%, σ phase is precipitated in the alloy above 600℃. Therefore, the content range of Ta element is determined to be 0-1 at.%.

[0046] The above embodiment can significantly improve the high-temperature mechanical properties of the alloy by designing the alloy composition and using non-continuous ε phase precipitation to obtain nanoscale ε lamella on the γ matrix, thereby solving the problem that ε phase cannot provide sufficient high-temperature strength.

[0047] Another embodiment of the present application provides a nanolamellar ε phase strengthened nickel-based multi-principal element alloy obtained by using the above design method, which comprises a matrix γ phase and a nanoscale ε phase lamella, and the nanoscale ε phase lamella is uniformly distributed in the matrix γ phase. The composition of the nickel-based multi-principal element alloy includes, in atomic percentage: 22-25 at.% Co, 22-25 at.% Cr, 1-4 at.% Nb, 0-4 at.% V, 0-1 at.% Ta, and the balance being Ni.

[0048] In some embodiments, the volume fraction of the nanoscale ε phase lamella in the nickel-based multi-principal element alloy is 15%-40%. When the volume fraction of the nanoscale ε phase lamella in the nickel-based multi-principal element alloy exceeds 40%, the plasticity is significantly reduced.

[0049] In some embodiments, according to the volume fraction of the nanoscale ε phase lamella in the nickel-based multi-principal element alloy, the lamellar spacing of the nanoscale ε phase lamella is 120-200 nm, and the lamellar thickness is 30-50 nm, which can make the alloy maintain good plasticity.

[0050] In some embodiments, the nanoscale ε phase lamella and the matrix γ phase are in a coherent state, and the mismatch degree is 1-3%, preferably 1.48%. The smaller the mismatch degree, the greater the coherence degree between the ε phase and the matrix, and the better the organizational stability.

[0051] Another embodiment of the present application also provides a preparation method of the nanosheet ε phase strengthened nickel-based multi-principal element alloy as above, comprising:

[0052] S1, first melt the component raw materials of the nickel-based multi-principal element alloy, and perform high-temperature homogenization treatment;

[0053] S2, then perform alloy cold rolling treatment;

[0054] S3, then perform recrystallization treatment;

[0055] S4, finally perform aging treatment at the temperature at which ε phase discontinuous precipitation occurs, to obtain the nanosheet ε phase strengthened nickel-based multi-principal element alloy.

[0056] In some embodiments, the component raw materials of the nickel-based multi-principal element alloy are melted and high-temperature homogenization treatment is performed, wherein: the temperature of the homogenization treatment is 1180-1230°C. The homogenization temperature is determined according to the Thermo-Calc thermodynamic calculation result, and is selected to be in the γ single-phase region, aiming to obtain a single-phase γ alloy, which can facilitate subsequent cold rolling processing and avoid cold rolling cracking.

[0057] In some embodiments, the alloy cold rolling treatment is performed, wherein: the deformation amount of the cold rolling treatment is greater than 80%.

[0058] In some embodiments, the recrystallization treatment is performed, comprising: recrystallization treatment at 1130-1200°C for 5-8 minutes. The recrystallization temperature is determined according to the Thermo-Calc thermodynamic calculation result, and is selected to be in the γ single-phase region, with the temperature being as low as possible to facilitate control of the grain growth after recrystallization. The cold rolling recrystallization is mainly for grain refinement, because the alloy after melting usually has large grains, and the cold rolling recrystallization can significantly refine the grains.

[0059] In some embodiments, the aging treatment is performed at the temperature at which ε phase discontinuous precipitation occurs, wherein: the temperature at which ε phase discontinuous precipitation occurs is 780-820°C, and the aging treatment is performed for 5-1000 hours.

[0060] In a preferred embodiment, the preparation method of the nanosheet ε phase strengthened nickel-based multi-principal element alloy comprises:

[0061] S1, prepare each element material according to the components of the nickel-based multi-principal element alloy as above, and place the prepared each element material into a high-frequency induction melting furnace; it should be noted that the nickel-based multi-principal element alloy can also include unavoidable impurities. Adjust the current to 40-60 A to make the each element material melt uniformly, and cast into an alloy ingot in the shape of a cuboid to facilitate subsequent cold rolling. After the alloy ingot of S1 is solid solution treated at 1200°C in air for 6 hours, it is water quenched.

[0062] S2, the alloy ingot is cold-rolled, the cold-rolling deformation is greater than 80%, and the alloy plate is rolled.

[0063] S3, the alloy plate is recrystallized at 1150 DEG C in air for 7 minutes, and then water quenched.

[0064] S4, the alloy plate is aged at 800 DEG C in air for 5-1000 hours, and then water quenched.

[0065] The alloy is discontinuously precipitated at 780-820 DEG C, and the epsilon phase with nanosheet structure is precipitated. The preparation method of the nanosheet epsilon phase strengthened nickel-based multi-main element alloy only needs traditional smelting-heat treatment, has short process and high efficiency. The nanosheet epsilon phase formed in the embodiment can significantly improve the high-temperature mechanical properties of the nickel-based alloy, the yield strength at 25 DEG C is increased by 90-120%, and the yield strength at 700 DEG C is increased by 70-100%, which provides technical support for solving the problem that the epsilon phase of the nickel-based high-temperature alloy cannot provide sufficient high-temperature strength.

[0066] The technical scheme of the present application is further described below with more specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form.

[0067] Embodiment 1

[0068] S1, 5 kg of alloy is prepared, and the composition is Co: 24 at.%; Cr: 24 at.%; Nb: 4 at.%; Ni: balance;

[0069] The prepared material is placed in a high-frequency induction melting furnace, the current is adjusted to 50 A, and the raw materials are uniformly melted and poured into several rectangular ingots with a thickness of 30 mm and a length of 150 mm;

[0070] The alloy ingot is solid solution treated at 1200 DEG C in air for 6 hours, and then water quenched;

[0071] S2, the alloy ingot after solid solution treatment is cold-rolled, and the plate after cold-rolling of 5 mm;

[0072] S3, the alloy plate after cold-rolling is recrystallized at 1130 DEG C in air for 8 minutes, and then water quenched;

[0073] S4, the alloy plate after recrystallization is aged at 800 DEG C in air for 1000 hours, and then water quenched.

[0074] As Figure 2As shown, the ε phase in the alloy is completely transformed into nanosheet morphology by discontinuous precipitation, and is uniformly distributed on the γ matrix. The Vickers hardness of the nanosheet strengthened alloy is about 312±9 HV. The hardness of the nanosheet strengthened alloy is significantly higher than that of the plate after recrystallization (without aging), which is about 177±5 HV.

[0075] Example 2

[0076] S1, proportioning 5 kg of alloy, the composition is Co: 22 at.%; Cr: 22 at.%; Nb: 4 at.%; V: 4 at.%; Ni: balance;

[0077] The proportioned material is placed into a high-frequency induction melting furnace, the current is adjusted to 50 A, so that the raw materials are uniformly melted, and several rectangular ingots with a thickness of 30 mm and a length of 150 mm are cast;

[0078] After the alloy ingot is solid solution treated at 1200°C in air for 6 hours, it is water quenched;

[0079] S2, the alloy ingot after solid solution treatment is cold rolled, and the plate after cold rolling to 5 mm;

[0080] S3, the alloy plate after cold rolling is recrystallized at 1160°C in air for 5 minutes, and then water quenched;

[0081] S4, the alloy plate after recrystallization is aged at 800°C in air for 700 hours, and then water quenched.

[0082] As shown, Figure 3 the ε phase in the alloy is completely transformed into nanosheet morphology by discontinuous precipitation, and is uniformly distributed on the γ matrix. The Vickers hardness of the nanosheet strengthened alloy is about 338±5 HV. The hardness of the nanosheet strengthened alloy is significantly higher than that of the plate after recrystallization (without aging), which is about 189±6 HV.

[0083] Example 3

[0084] S1, proportioning 5 kg of alloy, the composition is Co: 22 at.%; Cr: 22 at.%; Nb: 4 at.%; V: 4 at.%; Ta: 1 at.%; Ni: balance;

[0085] The proportioned material is placed into a high-frequency induction melting furnace, the current is adjusted to 50 A, so that the raw materials are uniformly melted, and several rectangular ingots with a thickness of 30 mm and a length of 150 mm are cast;

[0086] After the alloy ingot is solid solution treated at 1200°C in air for 6 hours, it is water quenched;

[0087] S2, the alloy ingot after solution treatment is cold-rolled, and the plate after cold-rolled to 5mm;

[0088] S3, the alloy plate after cold-rolled is recrystallized at 1150℃ in air for 7 minutes, and then water quenched;

[0089] S4, the alloy plate after recrystallization is aged at 800℃ in air for 100 hours, and then water quenched.

[0090] As shown in Figure 4 , the ε phase in the alloy is completely transformed into nanosheet morphology by discontinuous precipitation, and is uniformly distributed on the γ matrix. The Vickers hardness of the nanosheet strengthened alloy is about 427±7HV. The hardness of the nanosheet strengthened alloy is obviously higher than that of the plate after recrystallization (without aging), which is about 202±8HV. The yield strength of the nanosheet strengthened alloy at room temperature is 835.5MPa, as shown in Figure 5 , the room temperature yield strength of the plate without aging is about 380.2MPa, which is obviously lower than that of the ε nanosheet strengthened alloy. The yield strength of the nanosheet strengthened alloy at 700℃ is 668.8MPa; the room temperature yield strength of the plate without aging is about 338.3MPa, which is obviously lower than that of the ε nanosheet strengthened alloy. The nanosheet ε phase exhibits excellent strengthening effect at room temperature and 700℃.

[0091] Example 4

[0092] S1, 5kg of alloy is proportioned, and the composition is Co: 22at.%; Cr: 22at.%; Nb: 4at.%; V: 4at.%; Ta: 1at.%; Ni: balance;

[0093] The proportioned material is placed into a high-frequency induction melting furnace, and the current is adjusted to 50A to make the raw materials melt uniformly, and is cast into several rectangular ingots with a thickness of 30mm and a length of 150mm;

[0094] The alloy ingot is solution treated at 1200℃ in air for 6 hours, and then water quenched;

[0095] S2, the alloy ingot after solution treatment is cold-rolled, and the plate after cold-rolled to 5mm;

[0096] S3, the alloy plate after cold-rolled is recrystallized at 1150℃ in air for 7 minutes, and then water quenched;

[0097] S4, the alloy plate after recrystallization is aged at 800℃ in air for 5 hours, and then water quenched.

[0098] As shown in Figure 6As shown, the 5-hour aging treatment has made the ε phase in the alloy completely discontinuous precipitation transform into nanoscale lamellar morphology, and uniformly distributed on the γ matrix.

[0099] The above embodiments of the present application mainly rely on alloy composition design combined with process and heat treatment process optimization to obtain nanoscale ε lamellar reinforced nickel-based alloy, without adding noble metal elements, without using processing technology other than casting, cold rolling and heat treatment, and without increasing additional cost.

[0100] The above embodiments of the present application utilize the non-continuous precipitation of ε phase at 780-820℃ to prepare nanoscale ε phase lamellar reinforced nickel-based alloy; the nanoscale ε lamellar reinforced phase can significantly improve the mechanical properties at 25℃ to 700℃, increasing the yield strength at 25℃ by 90-120%, and increasing the yield strength at 700℃ by 70-100%; the nanoscale ε lamellar reinforced nickel-based alloy still maintains good plasticity (tensile elongation of 17%-25%) at 600℃ to 800℃.

[0101] The specific embodiments of the present application are described above. It should be understood that the present application is not limited to the specific embodiments described above, and various modifications or changes can be made by those skilled in the art within the scope of the claims, which does not affect the essential content of the present application. The above preferred features can be used in combination as long as they are not in conflict with each other.

Claims

1. A nanosheet-strengthened epsilon phase strengthened nickel-based multi-principal element alloy, characterized in that, The nickel-based multi-principal element alloy comprises a matrix γ phase and nanoscale ε phase lamellas uniformly distributed in the matrix γ phase, and the composition of the nickel-based multi-principal element alloy comprises 22-25 at.% Co, 22-25 at.% Cr, 1-4 at.% Nb, 4 at.% V, 1 at.% Ta, and the balance of Ni in terms of atomic percentage. The ε phase is a Ni3Nb phase, and Nb, V and Ta are all ε phase forming elements. The design method of the nanoscale ε phase lamellar reinforced nickel-based multi-principal element alloy comprises: The matrix elements of the nickel-based multi-principal element alloy are selected as Ni, Co and Cr, and the contents of the matrix elements in the master alloy are determined according to the Thermo-Calc thermodynamic calculation results; Nb, an ε phase forming element, is added to the master alloy to obtain as high ε phase solubility temperature as possible on the premise that no third phase other than γ and ε is precipitated, and the content of Nb is determined; V, an ε phase forming element, is added to obtain as high ε phase solubility temperature as possible on the premise that no third phase other than γ and ε is precipitated, and the content of V is determined; Ta, a strong ε phase forming element, is added to obtain as high ε phase volume fraction as possible on the premise that no third phase other than γ and ε is precipitated, and the content of Ta is determined. The preparation method of the nanoscale ε phase lamellar reinforced nickel-based multi-principal element alloy comprises: First, the component raw materials of the nickel-based multi-principal element alloy are smelted and subjected to high-temperature homogenization treatment; Then, the alloy is subjected to cold rolling treatment; Next, the alloy is subjected to recrystallization treatment; Finally, the alloy is subjected to aging treatment at the temperature at which ε phase discontinuous precipitation occurs, and the temperature at which ε phase discontinuous precipitation occurs is 780-820 ℃, thereby obtaining the nanoscale ε phase lamellar reinforced nickel-based multi-principal element alloy.

2. The nanochlamide epsilon phase strengthened nickel-based multi-principal element alloy according to claim 1, characterized in that, The volume fraction of the nanoscale ε phase lamellas in the nickel-based multi-principal element alloy is 15%-40%.

3. The nanochlamide ε phase strengthened nickel-based multi-principal element alloy according to claim 1, characterized in that, The lamellar spacing of the nanoscale ε phase lamellas is 120-200 nm, and the lamellar thickness is 30-50 nm.

4. The nanochlamide ε phase strengthened nickel-based multi-principal element alloy according to claim 1, characterized in that, The nanoscale ε phase lamellas and the matrix γ phase are in a semi-coherent state, and the mismatch degree is 1-3%.

5. The nanochlamide ε phase strengthened nickel-based multi-principal element alloy according to claim 1, characterized in that, The component raw materials of the nickel-based multi-principal element alloy are smelted and subjected to high-temperature homogenization treatment, and the homogenization treatment is performed at a temperature of 1180-1230 ℃.

6. The nanochlamide ε phase strengthened nickel-based multi-principal element alloy according to claim 1, characterized in that, The alloy is subjected to cold rolling treatment, and the deformation amount of the cold rolling treatment is greater than 80%.

7. The nanochlamide ε phase strengthened nickel-based multi-principal element alloy according to claim 1, characterized in that, The recrystallization treatment comprises recrystallization treatment at 1130-1200 ℃ for 5-8 minutes.

8. The nanochlamide ε phase strengthened nickel-based multi-principal element alloy according to claim 1, characterized in that, The alloy is subjected to aging treatment at the temperature at which ε phase discontinuous precipitation occurs, and the aging treatment is performed for 5-1000 hours.

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